I find it odd that said person would use that as an excuse when it doesn’t apply to their own games.
Pointing out the fact that feats are optional merely undercuts the
excuse "but, fighter's can spend their first bonus feat at 6th level to... " ...fix everything wrong with the class, really.
No, they can put their first bonus ASI at 6th level to a +2 in some less-critical stat without 'falling behind' (or pulling ahead) of the next guy in terms of STR or DEX (depending on which way the fighter went), or,
if the DM has opted-into Feats, grab their 2nd- (or 3rd if variant human) priority feat two levels earlier than the next guy.
Now, if feats were standard (yeah, some DMs might opt out of them, but standard is standard), and fighter's got their first bonus feat at first level (like they did in 3e), y'might have a stronger point.
Especially if they could retrain it frequently, oddly enough.
Some people won't be happy until fighters have something unique that only they have that no other class has an option to obtain
Like Action Surge?
They will always be compared to the standard of classes that are designed to be weaker at combat while better outside of combat
What 5e class is actually like that? I mean, noticeably ineffectual in the combat pillar? I can see how you could willfully design a character and intentionally learn only non-combat spells (I don't think you'd run out of choices too soon), to be that way, but no class that /is/ particularly weak at combat, without going a little out of your way to force it to be.
Fighters don't need to be the Mary Sues of classes.
See, that wouldn't be unique, either, because we already have the Bard. (j/k ...though if anyone's going name their character Mary Sue rather than Bob...)
fighters can get really close by using their two bonus feats.
Fun fact: Feats are still optional.